Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753249Ab2EHIOe (ORCPT ); Tue, 8 May 2012 04:14:34 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:50677 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751075Ab2EHIOc (ORCPT ); Tue, 8 May 2012 04:14:32 -0400 Date: Tue, 8 May 2012 01:13:06 -0700 From: Anton Vorontsov To: KOSAKI Motohiro Cc: Pekka Enberg , Minchan Kim , Leonid Moiseichuk , John Stultz , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, patches@linaro.org, kernel-team@android.com Subject: Re: [PATCH 3/3] vmevent: Implement special low-memory attribute Message-ID: <20120508081305.GA20574@lizard> References: <4FA35A85.4070804@kernel.org> <20120504073810.GA25175@lizard> <20120507121527.GA19526@lizard> <4FA82056.2070706@gmail.com> <20120508065829.GA13357@lizard> <4FA8C86B.8010205@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <4FA8C86B.8010205@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1185 Lines: 28 On Tue, May 08, 2012 at 03:16:59AM -0400, KOSAKI Motohiro wrote: [...] > >So, feel free to call me an idiot, but please expand your points a > >little bit or give a link to the discussion you're referring to? > > I don't think you are idiot. But I hope you test your patch before submitting. > That just don't work especially on x86. Because of, all x86 box have multiple zone > and summarized statistics (i.e. global_page_state() thing) don't work and can't > prevent oom nor swapping. Now I think I understand you: we don't take into account that e.g. DMA zone is not usable by the normal allocations, and so if we're basing our calculations on summarized stats, it is indeed possible to get an OOM in such a case. On Android kernels nobody noticed the issue as it is used mainly on ARM targets, which might have CONFIG_ZONE_DMA=n. So, this particular issue makes sense now. Thanks! -- Anton Vorontsov Email: cbouatmailru@gmail.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/